Meeting Abstract
P3.80 Monday, Jan. 6 15:30 Consequences of thermal variability on flexibility of avian metabolic performance HALLOT, F.*; DUBOIS, K.; MILBERGUE, M.; PETIT, M.; LE FRANÇOIS, N.R.; VÉZINA, F.; Univ. du Québec à Rimouski (Canada) – CSBQ- CEN – BORÉAS fanny.hallot@uqar.ca
With climate change it is expected that temperature variations will increase in frequency and amplitude. Since temperature strongly affect energy budget of homeotherms through thermoregulatory requirements, increased temperature variability could lead to effects on individual physiological performance and fitness. In theory, animals should be able to adjust to temperature variations through thermal acclimatization and this should allow them to buffer, up to a certain limit, the effects of increased variability in temperatures. However, in avian systems little is known of the effect of temperature variations on the pattern of thermal acclimatization. Using captive zebra finches (Taeniopygia guttata) as our model species, we conducted an experiment to determine whether recent thermal variations affect the rate of individual metabolic adjustments to subsequent changes in ambient temperatures. Two groups of birds were kept for 7 weeks to either a constant (21°C) or variable (fluctuating between 35°C to 7°C every 7 days) temperature treatment. Then each group was divided into two subgroups, which were exposed to a constant cold (7°C) or constant warm (35°C) temperature for 5 weeks. During this second period, metabolic parameters (basal metabolic rate; BMR and maximal thermogenic capacity; MSUM) were measured weekly on all birds in order to measure the rate of change and amplitude of metabolic adjustments (difference in values between 7°C and 35°C). Data were being analyzed at time of submission. We expect a higher rate of change and higher amplitude of metabolic performance in individuals previously exposed to temperature variations than in those maintained at stability.
